In a typical process control system for a fast changing or volatile process, execution of control strategies often requires that the control system be deterministic. However, quite often there is a need to perform some operations as part of the control strategy that are not deterministic with regards to time. For example, calculating over a large number of process data points or accessing computer disk files can take an indeterminate amount of time.
This problem typically requires a control engineer to employ a different design model to manage and execute the non-deterministic control algorithms, which results in added costs and complexity. Control engineers desire an integrated, single control system for both deterministic and non-deterministic algorithms.